Device for dispension

ABSTRACT

The present invention relates to a device for dispensing a medicament from a pressurised canister comprising a mouthpiece, a seat for engagement with the top of the canister and a housing provided with means for guiding and/or holding the canister.

FIELD OF THE INVENTION

The present invention relates to a device for dispensing a medicamentfrom a pressurised canister where the device comprising a mouthpiece, aseat for engagement with the top of the canister and a housing providedwith means for guiding and/or holding the canister.

BACKGROUND IF THE INVENTION

These types of devices are used as portable inhalation devices whichpermit the user to inhale a medicated vapour spray where the spray mayinclude powders, liquids or gasses.

These types of devices are usually used by people suffering from asthmaand other respiratory diseases or disabilities having difficultybreathing from time to time. Depending on the activity level of theperson in question, the breathing difficulties may be more or lesssevere. Also inflammations or other infections or secondary diseases inthe respiratory system can further aggravate the difficult breathingsituation.

Asthma inhalation devices function in a way whereby the user/patientwhen needing to inhale the medication places the asthma inhalationdevice with a mouthpiece in the patient's mouth and thereafter activatesa button. By depressing the button a canister inside the device isactivated such that a medication dose stored in the valve system in thecanister is dispensed through the mouthpiece to the patient.

A number of medications are available in order to alleviate thesesymptoms and substantially restore the individual's ability to breatheto a normal stable situation.

Although there are a number of different ways in which to takemedications for alleviating the problems mentioned above, one of themore common types is to have the medication mixed with an aerosolpropellant in a canister. The canister in then placed in an inhalationdevice whereafter the individual suffering from breathing problems caninsert a mouthpiece into the mouth and by depressing the canister in thedevice dispense a dose of the medication directly into the airways.

The canister is usually placed upside down in the device, see forexample EP 476991, such that the dispensing nozzle and/or the rim, i.e.the ferrule as well as the stem of the canister, are pointing downwardsin the inhalation device. The stem rests on a seat and is guided suchthat upon depression of the canister by the user's hand into the device,the nozzle will be depressed and due to the overpressure created by thepropellant in the canister, a dose will be sprayed into the user'smouth. The user will then inhale the aerosolised medication directlyinto the lungs.

The device disclosed in EP 176991 further discloses a pivotable member,which in a closed position covers the mouthpiece and in an activeposition is pivoted into a position where the member engages the bottomof the canister and acts as a lever arm for depressing the canister.

It is a requirement that canisters of this type are fitted with a valvesystem whereby depression of the canister and thereby dispensing ofmedication through the stern/nozzle is provided such that only onesingle dose per compression will be dispensed.

Conventional dispensers are usually two-piece structures consisting of ahousing which contains the mouthpiece which is also adapted to receivethe aerosol canister wherein the medication is contained. The medicationis contained in the canister under pressure due to the presence of anaerosol. The canister is inserted into the housing so that thedispensing nozzle of the canister is pointed downward and orientedtowards the mouthpiece provided on the housing as is the case in EP476991. The opposite end of the canister usually projects upwardly andoutside the housing. The user can place the housing between the thumpand forefinger and use the thump and forefinger or the thump and fingersto force the canister downward and in this way release a dose of themedication into the mouthpiece and thereby inhale it into the airwaysand lungs.

For individuals suffering from mild forms of asthma or other breathingdisabilities, depressing the canister into the device and therebydispensing a dose does usually not cause a problem. However, a largenumber of the users of these types of devices are also suffering fromother debilitations such as rheumatism or arthritis. Furthermore, smallchildren needing asthma medications may also find it difficult to gripthe prior art devices as mentioned above in that their hand arephysically to small in order to be able to grip around the device andexert the necessary force in order to dispense a dose. A number ofdevices are therefore proposed which should aid especially users withreduced physical ability to depress the canister in order to dispense adose. Such devices are presented in U.S. Pat. No. 6,397,837, EP 476991and U.S. Pat. No. 4,834,083 wherein the traditional inhalation devicecan be equipped with a lever arm device mounted on the traditionalinhalation device.

One problem associated with some of the devices mentioned above is thatthe lever arrangement either must be installed before every dispensingof a dose. This can cause serious problems for the user in that usuallywhen a dose is needed, the user's ability to breathe is hampered and thestress level for the user is therefore increased. In order to assemblethe device such that a dose can be dispensed, more parts have to berelocated and assembled on the device. Another problem is that for ahost of users it is desirable to carry the device around with them suchthat a dose can be dispensed whenever needed i.e. in the office; on thebus etc. For this purpose the users often carry their dispensing devicein a pocket or in a small handbag. With the lever arm arrangementaccording to the prior art mentioned above there is a tendency that thelever arm may become stuck since it projects outside the generalgeometry of the device itself as seen in for example U.S. Pat. No.6,397,837 and EP 476991. This in turns means that either the device willbe broken off and therefore not function or the lever arm arrangementwill be disassembled causing extra trouble for the user when a doseneeds to be dispensed.

For a number of users suffering from diseases where the medication isdispensed in the manner described above they will have differentcanisters containing different concentrations of the medication or evendifferent types of medication for different diseases. The canistersand/or devices are often colour-coded in order to provide informationabout the medications contained in the canister. It is however a problemfor the user always to have the correct canister mounted in the deviceas well as some of the devices are made in such a way that it isimpossible to recognise the colour-coding on the canister as usually alarge part of the canister is placed inside the dispensing device. It istherefore foreseeable that a situation can arise where a personsuffering from any of the debilitations mentioned above will findhim/herself in a situation with the wrong medication and further mightinadvertently dispense a dose of a wrong medicament due to the inabilityof recognising the canister in the device.

Depressing the canister in order to dispense a dose can require anamount of force which for some users creates uncertainty whether a dosehas been fully dispensed or not, due to the user's limited strength. Asa number of the users as explained above can have limited force in theirhands it becomes increasingly difficult for these persons to dispensedoses when needed.

Recently the legislative bodies in the different countries have mademoves to ban the CFC-gasses which are traditionally used as aerosols incanisters of this type. CFC-gasses are being replaced by a new family ofgasses known as HFA-gasses. These gasses when used asaerosols/propellants require that the gaskets and the valve arrangementin the canister are made in a different manner. For the user the resultis that a higher force is needed in order to compress the canister intothe inhalation device whereby the nozzle is sufficiently compressed forit to dispense a dose of the medication. As a number of the users asexplained above can have limited force in their hands it becomesincreasingly difficult for these persons to dispense doses when needed.A further consideration both for producers and for the users of thistype of device is the hygienic circumstance in which the device as awhole but especially the mouthpiece is manufactured, handled, stored andkept by the user.

Some patients suffering from asthma or other respiratory diseases oftensuffer from other related diseases such that it is important that themouthpiece is kept as clean as possible.

In order to protect the mouthpiece, it is customary to provide a loosecap which snugly fits onto the mouth piece. This cap however, has atendency to become lost, damaged or otherwise not fulfil its function.In order to alleviate this it has been suggested in the art to fastenthe cap to the device itself, for example by means of a strap or toarrange a hinge such that the cap member can be pivoted into a closedposition as is the case I EP 476991. In all the prior art devices whereattachment means have been provided for keeping the cap in closeproximity to the device as such, the cap can obstruct the usability ofthe device and hamper the dispensation of a medication dose.

A different solution is proposed in U.S. Pat. No. 4,834,083, where a capis not provided as such. The space in which the nozzle and valve of thecanister is placed is separated from the outside by a slidable closuregate.

The device as disclosed in U.S. Pat. No. 4,834,083 further discloses anarrangement for avoiding accidental dispensation of a dose. When thecanister is placed inside the device, the lever arm is pivoted into aclosed position covering the canister. The lever arm is provided withtwo projections—a latch and a stop. When closing the lever, the latchengages a hook section provided in the housing. The stop projectsthrough an aperture in the housing for engagement with a catch. In orderto prepare the device for use the gate shall be raised, whereby the gateshall deflect the stop from its engagement with the catch. As the leveris depressed, both the latch and the stop may be further deflected dueto engagement with the housing in order for the lever to be able to movedownwards. A number of drawbacks are connected with this construction.As the stop is arranged in a aperture in the housing and the gate actson the stop adjacent the aperture, the forces needed for deflecting themember sufficiently are high. The deflection is, furthermore, limited bythe latch which altogether hampers the depression of the canister. Thespace between the stop and the latch is very limited and if foreignmatter becomes stuck, the operation of the device is severelyobstructed.

On the other hand, after a number of deflections the stop may haveattained a substantial permanent deflection such that accidentaldispensation of a dose may occur. Productionwise is may also bedifficult to control the process as the latch and stop members must beseparated and precisely spaced and curved in order to be able tocooperated with corresponding elements in the housing.

In order to be able to describe the canister in detail and how thedifferent parts and sections of the device are arranged in relation toeach other, the relative terms “inside”, “outside”, “up”, “down”, “infront of” and “behind” shall be interpreted as imagining the device inthe user's mouth in the use situation i.e. in a situation where a useris standing vertically and inserts the device having the canister in asubstantially vertical position with the stem and nozzle section andferrule of the canister placed such that the stem and nozzle candispense a dose out through the mouthpiece. In this position thecanister containing the medication is above the stem. Consequently, thebottom of the canister is the end with the ferrule and the stem/nozzle.The opposite end is designated the top. In front of the canister, meansthat it is close to the user's face i.e. on the same side as themouthpiece, and behind the canister is to be understood as being awayfrom the user's face. Inside the housing is to be interpreted as beingwithin the volume comprised within the housing. Horizontal isconsequently defined in relation to the above described use position.

SUMMARY OF THE INVENTION

Consequently, it is an object of the present invention to provide adevice for dispensing a medicament as described above which provides foreasy, reliable and safe dispensation of a dose and which furthermorealleviates the drawbacks of prior art devices as mentioned above.

One very important aspect of the invention is to provide for a reliabledose counting such that a user may rely on the information providedrelating to the actual amount of doses left in the device.

General Device

The invention addresses this problem by providing an inhaler device fordispensing a medicament from a pressurised canister, where said devicecomprises a mouthpiece arranged in a housing, where said housingsubstantially encloses the canister, where a lever arm is provided,where said lever arm comprises means for engaging the bottom of thecanister such that said lever arm may be activated by a user in order todispense a dose, peculiar in that the lever arm further engages a yokewhere the transfer of movement from said lever arm due to the activationof said lever arm to the yoke is linear and/or non-linear, and that theyoke comprises means for transferring the movement to a dose countingmechanism arranged in the housing.

By providing the transfer of the activation movement to the yoke, itbecomes possible to control the input to the dose counting device. Itis, as discussed above, known to use a lever arm in order to reduce theforce necessary to dispense a dose. The actual movement of the canisterin order to activate the valve of the canister is, however, very small.If the dose counter, therefore, is activated by the very limitedmovement of the canister, the occurrence of manufacturing tolerances,i.e. play in the device, may give rise to “false” counts. Therefore, bytransferring the activating movement to a yoke, it becomes possible toboth isolate and differentiate the activation movement into a dosedispensation and a counting movement.

In order to further exploit the possibilities of utilising the yoke, themovement of the canister caused by said lever arm in order to dispense adose is shorter that the corresponding movement of said yoke.

In this manner, it is achieved that the very limited movement of thecanister in order to dispense a dose is transformed into a relativelylarge movement in the yoke such that a more determined input may bedelivered to the dose counting mechanism.

The invention further addresses the object stated above by providing adevice for dispensing a medicament which is special in that a lever armhaving means for engagement with the bottom end of the canister suchthat the canister is not accessible form the outside, where a seat forengagement with the top of the canister is provided inside the housing,and a cap is pivotally arranged such that the cap can be pivoted into aclosed position where it covers the mouthpiece and an open positionwhere the mouthpiece is accessible, and that said cap further comprisesmeans for abutting the top of the canister and/or for abutting the meansfor engagement with the bottom end of the canister when the cap is inits closed position such that the canister cannot be activatedaccidentally

By providing a lever arm, the amount of force needed by the user todepress the canister is lessened. This is especially important with thenew type of propellants/aerosols in that the seals and gaskets in thecanister around the nozzle makes it more difficult i.e. requires higherforces in order to compress the canister enough for a dose of medicationto be dispensed.

Contrary to prior art devices, in a preferred embodiment the lever armis only projecting outside the housing when the means for engagement ofthe bottom end of the canister is engaging the canister.

Alternatively, the lever arm is provided flush with the housing. Thelever arm still provides the advantages as explained above, butadditionally provides for a simpler construction. In use this embodimentprovides the user with more possibilities for holding and activating thedevice. At the same time when the lever arm is a free moving part, butintegral/flush with the outer surface of the device, easy and unhinderedstorage of the device is assured. Furthermore, foreign matter cannotenter the device and accidentally hinder activation of the drugdispensation or an optional dose dispensing device. In one actualembodiment of the device the lever arm is the activating button Thebutton is arranged such that an air gap between the button and thehousing lets in the air required for being able to inhale the dispenseddose through the mouthpiece.

Furthermore, as there are no projecting members of the device, itbecomes easier to store in a pocket, handbag or the like and furthermorethe risk of damaging the device is minimal due to the protective housingsurrounding the device as such.

Turning to the more specific construction of the device, the device in afurther preferred embodiment of the invention is constructed such thatthe means for engaging the bottom of the canister are integral with thelever arm. When the lever arm and the means for engaging the bottom ofthe canister is one and the same member, for example constituting anoutside surface of the housing, fewer parts are needed in the assemblyof the device. This has some advantages in the fact that the fewer partscomprised in the device, the fewer parts can be misassembled ormalfunction during the device's expected lifetime. Furthermore, byintegrating the means for engaging the bottom of the canister in thelever arm, the effect of the lever arm is maintained and the device ispresented as an integral unit without any members extendingsubstantially outside the housing of the device, especially when the capis in its closed position.

The lever arm's function is mainly to reduce the force necessary todispense a dose as explained above. This is particularly true for thecanisters comprising HFA-propellants/aerosols where gaskets of adifferent type are needed in order to make the canister leak proof.These gaskets require a higher force in order to depress the canisterfor dispensing a dose. The lever arm is therefore in a further preferredembodiment constructed such that the lever arm has a lengthcorresponding to increasing the actual force delivered to the bottom ofthe canister by the engagement means by a ratio in the range of from 2:1to 5:1, most preferred around 3:1.

A further advantage in increasing the force transferred to the canisteris that it is assured that a positive dispensation and completedepression of the canister can be obtained since it will be easier forthe user to depress the lever arm completely. Also by providing a leverarm, the need to use force by the user diminishes in that the lever armmultiplies the force. Furthermore, a better coordination between theactivating movement e.g. the depression of the lever aim and theinhaling of the dispensed dose is achieved.

In a further preferred embodiment, the lever arm is a pivotal section ofthe housing constituting at least part of the top surface of the deviceand the lever arm is pivotally fastened to the housing in one end of thelever arm. Also in a still further embodiment, the lever arm adjacentits free end comprises a downwardly projecting hook section and acorresponding grip section is arranged on the inside of the housing suchthat the hook and the grip section can be brought into abutting contactand thereby create a snap-joint.

As the lever arm in this embodiment of the invention also is a part ofthe housing, it is important for the integrity of the housing that thelever arm is kept in a position where it is flush with the rest of thehousing. The hook and grip sections when engaged by the snap-actioncreating the snap-joint provide for the downward depression movement ofthe lever when the means for engaging the bottom of the canister isactivated such that an unproblematic ejection of a dose can beperformed. When the canister moves back up and thereby pushes theengagement section up. The upward movement of the canister is limited byits ability to reset and the lever arm being a section of the housinghas a limited movement due to the fact that the hook section abuts thegrip section. By adjusting these two, it is possible to ensure that thelever arm does not engage the bottom of the canister and at the sametime that the surface of the lever arm is kept at a level where the topsurface of the lever arm is substantially flush with the rest of thehousing.

The Cap

By further providing a cap for covering the mouthpiece it is achievedthat the part of the device adapted to be inserted into the oral cavityof the user is kept as cleans as possible. The cap is pivotally mountedto the housing such that it can pivot between a closed position wherethe mouthpiece is completely covered and an open position in which themouth piece is accessible.

The pivotally mounted cap makes sure that the cap is always availablefor covering up the mouthpiece when the mouth piece is not to be used.Although this does not constitute a 100% hygienic protection for themouth piece, it does provide protection against dust, sand and otherforeign objects which might otherwise become stuck either inside themouthpiece or on the surface of said mouth piece. By being able to pivotthe cap away from covering the mouth piece and into an open positionwhere the mouthpiece is not hindering the access to the mouth piece,both the hygienic protection of the mouthpiece as well as the safekeeping of the cap is assured.

Additionally, the cap comprises means which means in the caps closedposition abuts/engages the top of the canister, whereby downwardmovement of the canister is prevented and thereby prevents thedispensing of a dose. By positively locking the canister in thisposition wherein it is impossible for it to be activated in order todispense a medicine dose through the nozzle, it is assured that thedevice as such will not dispense a dose inadvertently. It requires apositive action from the user side, namely the pivoting of the capmember in order to firstly gain access to the mouthpiece through whichinhalation of the medication is done and at the same time releasing thecanister from a locked position such that upon activation of the meansfor engaging the bottom of the canister, the top of the canisterincluding the nozzle means can be brought into a position where amedication dose can be dispensed.

The means for abutting/engaging may alternatively act on the means forengagement with the bottom end of the canister when the cap is in itsclosed position such that the canister cannot be activated accidentally.

In a further advantageous embodiment a shaft projecting out of thehousing engages at least one aperture provided in the cap or adepression on the inside of the cap. This arrangement can, however, alsobe arranged such that the depression or aperture is arranged in thehousing and the engaging shaft is provided on the cap. On the inside ofthe cap adjacent the aperture or depression a cam is provided. Thehinge-like arrangement of the cap constitutes a simple and a costeffective way of arranging the cap on the housing.

In a further advantageous embodiment the means for engagement with thebottom of the canister comprise a yoke which yoke has a canisterengagement section optionally having a shape corresponding to the bottomof the canister and an end section which, when the cap is in its closeposition, engages the cam provided on the cap such that the engagementsection of the yoke is not in contact with the canister.

This mechanism makes certain that the engagement means not accidentallycan be activated and the canister depressed. By depressing the canister,the nozzle will be activated and a dose will be dispensed. It istherefore not desirable to have an uncontrolled dispensing ofmedication. This is assured by having a mechanism which, when the cap isclosed, hinders the movement of the engagement means by making the yokenot moveable in a non-engaging position.

In a still further advantageous embodiment means are arranged in the capfor engagement with the housing and limiting the cap's movement withrespect to the housing in the cap's open position. Hereby it is assuredthat the cap, when it is open, can come into a firm position against thehousing and thereby constitute a reaction surface. When a person wantsto dispense a dose of medication, the device is usually gripped asdescribed above in the hand of the user. This means that one part of theuser's hand usually the thump will be placed underneath the device andin this embodiment a surface of the cap will constitute the grippingsection, whereas a forefinger will grip and depress the lever arm. It istherefore important that the cap in its open position gives the user afirm grip upon activation. It is therefore in a still furtheradvantageous embodiment of the invention so that the underside of thecap in its open position constitutes a grip and that the grip optionallyis ergonomically shaped. The economic shape can be attained by givingthe surface in question a saddle-shape. With “saddle-shape” should beunderstood a surface which curves in two directions so that it willsnugly fit into a finger joint, for example in the thumb. Furthermore,the surface of the cap can have a character which gives it non-slipproperties, for example by roughening the surface by providing dimplesor even by adding a high friction layer to the surface.

In a further advantageous embodiment of the invention, the lever arm isguided by three tracks provided on the inside of the housing where theguidance comprises pins arranged on the lever arm perpendicular to thelever's longitudinal direction and that said pins engage the tracks andpreferable identical sets of tracks arranged symmetrically on eitherside of the lever: a first set of tracks in front of the canister whichis generally horizontal; a second set of tracks provided in the yokealso being generally horizontal and a third set of tracks arrangedbehind the canister and comprising a generally straight upper sectionand a curved lower section.

In a further advantageous embodiment of the invention, the length of thelever arm is such that when the cap is in its close position and thefree end of the lever arm is flush with or contained within the housingand when the cap is in its open position, the free end of the lever armwill project from the housing.

This interaction between the cap and the lever arm does in combinationwith the above mentioned embodiments of the invention that the device assuch has a very user friendly and storage friendly appearance. When thedevice is closed, there are no projecting members which can becomestuck, break or otherwise give rise to unfortunate incidents. In orderto activate the device, the user has to do a positive turning of the capin order to release the engagement means from the cam via activation ofthe yoke, make the lever arm project from the housing and thereaftergrip the device such that part of the users hand will rest on the gripprovided by the cap in its open position and thereafter depress thelever arm for dispensing a dose.

In a still further advantageous embodiment of the invention, the lowermost section of the yoke and the abutting section of the cam arecorrespondingly shaped such that a resilient member urging the yokeagainst the cam will provide a certain resistance against pivotalmovement of the cap in its close position. By providing the device withthese features, the user will have to make a positive turning of the capmember in order to overcome the resistance forces arising due to theabutting contact between the cam and the yoke. This is further assuredby the provision of a resilient member, for example in the shape of aspring which will maintain the yoke in an abutting relationship with thecam in the cap's close position.

The abutting section of the cam can be shaped with a convex or concavesection with a corresponding concave or convex section in the end of theyoke such that a positive close position will be felt by the user asthese abutting sections engage.

Also during storage and transport of the device, the positive engagementbetween two abutting sections will minimize the risk of the deviceaccidentally opening.

Dose Counting

An additional problem associated with this type of device is the factthat a canister can contain 100 or more doses of medication. The userwill therefore have a tendency to forget how many doses have beendispensed or how many doses are left in the device. This can give riseto severe problems especially if the user is travelling and thereforedoes not have access to the regular supply of medicaments should thecanister run empty.

Furthermore, in certain situations it is desirable to have an indicationabout when a new canister/device should be bought. For some types ofmedication it is becoming a legal requirement that an indicating deviceshall be provided for this type of devices. It is therefore in a stillfurther advantageous embodiment of the invention foreseen that a user isable to see how much is left in the canister by means of a dosedispensing mechanism arranged inside the housing such that a memberengaging the rim of the canister will be depressed together with thedepression of the lever arm and that said member will transmit thedepression to a dose dispenser for registration of a delivered dose andthat the dose dispensing mechanism comprises means visible on thehousing for indicating the number of dispensed doses or the number ofremaining doses.

Either indication i.e. whether it is the number of dispensed doses orthe number of remaining doses is interesting information for the user.When indicating the number of dispensed doses it is necessary to knowthe total number of doses contained in the canister whereas when thedose dispensing mechanism indicates the number of remaining doses, it isnecessary to set the dose dispenser when the canister is inserted on thecorrect number of doses contained in the canister. Alternatively, if itis not desirable to indicate an exact number, the dose dispenser can bearranged to indicate when there is a low dose content in the canister,for example by the lettering “low” or by indicating with a colour codeon the readout that only a limited number of doses is available from thecanister.

In an embodiment of the invention the dose indicating mechanism isarranged as an integral part of the canister holding means. In this wayit is impossible to disengage the indicating means from the canister,whereby errors arising due to inadvertently replacing one canister withanother and in this manner perhaps get a wrong content indication can beavoided. Furthermore, the holding means can be provided such that thecanister cannot be removed from the holding means.

A dose dispensing device is disclosed, which benefits from the inputfrom the lever arm as described above in that the lever arm causesanother large movement/displacement. This displacement makes it easy todetect that an intentional dose has been dispensed or is in the processof being dispensed in that the signal from the lever arm is clear andeasily detectable.

In the art there is suggested a number of dose dispensing mechanism,where saw teeth on an indicating wheel are pushed forward by a moveablemechanism, for example in the shape of a secondary lever arm. Thesecondary lever arm is often activated by the canister's movement andthe entire travel length of the secondary lever arm corresponds to thetravel length of the canister during the dispensation of a medicationdose. There are, however, in the beginning of the movement as well as inthe end of the displacement of the secondary lever arm a certaintolerance, which due to the very small displacements of the secondarylever arm in relation to the saw tooth can give rise to inaccuracies inthe indication of the number of dispensed doses or, alternatively, thenumber of remaining doses in the canister. Consequently, there is a needfor a dose dispenser, which is more reliable and which operates withtolerances of a magnitude where they are negligible such that reliableinformation is indicated in the indicating wheels.

Providing for Determined Dispensation and Dose Counting

Due to production tolerances on the canister length and on the firepoint, i.e. the exact point in the movement of the input where a dose isdispensed from the canister, it is very difficult to ensure thatcounting will always happen before the fire point, but never twicewithin one actuation.

The two following conditions can hardly be fulfilled at the same time:

Count before releasing a dose.

Do not count two doses in one actuation.

One way of solving the problem is to arrange a linear or non-lineargearing element between the canister movement and the input to the dosecounter. By doing this, some part of the canister stroke will result ina relatively large input to the counter, while the other part of thecanister movement will result in a smaller input to counter. Inparticular the movement near the fire point can result in a relativelysmall input to the counter, while the beginning of the stroke can resultin a much bigger movement. In this way, the critical tolerances will beless disturbing, since they take up a smaller fraction of the movement.

In other words, the non-linear gearing element will “stretch” thereliable part of the canister movement and “compress” the criticaltolerances, thereby enabling the counter to safely display the actualnumber of doses left in the canister.

This aspect is further improved by the action of the lever arm when thetravel of the yoke is larger than the travel of the canister asexplained above.

In order to indicate the remaining content or used content in thecanister indicating devices comprising one or more wheels can beinstalled. The indicating devices are often installed such that the usereasily can determine the content directly by reading the dial(indicating wheels) arranged behind a transparent section of thehousing.

The indicating device may comprise one or more wheels arranged on acommon or on separate axles. On the one or more wheels are providedmeans for engagement with an input arrangement translating the inputfrom the user that a dose is being dispensed into an input that one ormore of the indicating wheels shall be moved correspondingly to indicatethat one more dose is being dispensed.

In one preferred embodiment two indicator wheels are provided on acommon axis. In front of the two indicator wheels, a front cover isprovided. In the front cover is provided a window area through whichmarkings on the two wheels can be viewed. On the front is in one exampleindicated the numbers 1 to 12 and next to each number arrangedcircumferentially along the periphery of the wheel is arranged a windowthrough which a small segment of the second wheel can be seen. On thesecond back wheel is circumferentially arranged the numbers 0 to 9twice. When the front cover and the two wheels are arranged such thatthe two wheels are arranged around the common axis, it will be possiblethrough the window area on the front cover to see one of the number 0-12including a window on the front wheel and through that window in thefront wheel see one of the number 0-9 on the back wheel. As each dose isdispensed, the back wheel will move onto the next number. The frontwheel will be activated to move by means of for example a gear wheelinterposed between the two indicator wheels such that the front wheelwill be activated to move one notch when the back wheel moves from 9 to0 or vice versa 0 to 9.

Through the window in the front cover, one or two digits on the frontwheel will be visible as well as through the window in the front wheelthe numbers on the back wheel will be visible. In this manner it ispossible to provide an exact counter of the number of dispensed dosesindicating either the number of remaining doses or the number ofdispensed doses.

Above the back wheel was described as having the numbers 0 to 9illustrated twice along the circumference. However, the back wheel canalso be numbered from 0 to 9 and therefore only contain ten digits orindicate the numbers 0 to 9 three times and therefore comprise thirtydigits or more. The choice depends on how the input is transmitted inorder to activate the dispensing device.

The two wheels can also have different diameters such that the frontwheel has a smaller diameter than the back wheel whereby it will bepossible, without a window in the front wheel, to view the numbers onthe back wheel.

Advantages of the Yoke—Dose Counting Means

In an alternative embodiment according to the invention a dose dispenseris disclosed, which dose dispenser comprises indicating means forindicating the available content in the canister, which means comprisestwo indicating wheels turnably arranged on respective perpendicularaxis; a secondary lever arm having means for engaging at least one ofthe indicating wheels; a pivotable activating member comprising a linearand/or a non-linear section arranged such that the secondary lever armwill abut and slide on said linear and/or non-linear section during acount.

In a further preferred embodiment the linear and/or non-linear sectioncomprises a first curve or a circular section translating into a secondcurve or linear section translating into a third curve or a circularsection.

In this manner a count, i.e. registration and indication of a dispenseddose, comprises three distinct movements by the secondary lever armengaging the indicating wheels. The first movement is caused by theprotrusion sliding along a first curve/circular section. By thismovement the protrusion on the lever arm engaging the indicating wheelis brought into engagement with engagement means arranged on theindicating wheel. Hereby any slack and tolerances in the system is takenout and the dispense mechanism is prepared for the count. The count isactivated by the protrusion sliding along the second, preferably linear,surface on the lever arm. As the lever arm has engaged and taken up anyslack in the system between the indicating wheel and the lever arm, thelever arm will be depressed and thereby the indicating wheel will beturned/rotated due to the sliding movement along the second surface. Asthe second surface translates into the third curved, circular shapedsurface the lever arm will not move any further thus allowing thecanister to be fully activated. In this manner a definite input iscreated by depressing the lever arm in order to activate the mechanismsuch that one dose is being registered in the indicating wheels.

In a further embodiment the pivotably fastened lever arm has anengagement point which engages a translating yoke, which yoke comprisesa projecting member which is adapted to engage a secondary lever armhaving means for translating the movement of the projecting member to adose counting mechanism, where the engagement point engages the yoke onan upper surface of said yoke.

By transferring the movement of the lever to the yoke, a rather longtravel of the active parts is achieved, whereby better accuracy relatingto the firing point may be achieved.

In a still further embodiment, wherein the lever arm's movement istransferred to the yoke, the upper surface of the yoke is linear, suchthat the engagement point transfers the movement of the pivotablymounted lever in a linear movement to the yoke.

In this embodiment the user will feel a smooth and constant movement ofthe lever as the engagement point slides along the linear top surface ofthe yoke.

In an alternative embodiment of the engagement point/yoke the uppersurface of the yoke is divided into two or more distinct linearsections, where the lever arms engagement points' travel along thesecond section creates a substantial part of the yoke's downwardmovement.

In this particular embodiment the lever arm's movement may be constantwhereas the yoke will travel downwards in different tempi, depending onthe linear sections arranged at the top of the yoke. In a particulardesired configuration, the first section is arranged such that theengagement point during its travel along this first section only willdepress the yoke very slightly. The yoke's movement may be compared toan initial movement taking up slack and tolerances in the device.

The second section may be very steep in relation to the engagementpoint's travel, whereby a rather large depression of the yoke occurs incomparison to the movement of the lever, and finally in a third sectionthe yoke's movement again in relation to the engagement point may benegligible as the movement is used to finish the movement or action bythe lever.

In a further advantageous embodiment of the invention a part activatedby the lever arm comprises engagement means for engaging the indicatingwheels. The indicating wheels can be supplied with a groove which isarranged in a circular surface of at least one of the wheels at adistance from the rim. The groove comprises spaced radial sectionsconnected with curved or linear sections. In a further embodiment saidgroove may for example comprise interconnecting and alternating radialand peripheral sections arranged such that a part of the lever arm isinserted and slidably arranged in said groove and further that means forurging at least one wheel to rotate is provided. The groove may also beshaped as a saw tooth track, wherein radial sections are interconnectedwith linear or curved sections (corresponding to the peripheralsections) alternating at either end of the radial section. Also, otherpatterns or designs of the groove can be contemplated within theprinciple of the rotation of the wheel being hampered by engagementmeans on a secondary lever arm engaging notches or the like (radialsections) on the wheel.

The groove will be a guidance track for the secondary lever arm'smovement. If the secondary lever arm encounters a radial section, thewheel will not be able to rotate further. By moving the secondary leverarm in a radial direction, i.e. depressing the canister and dispensing adose, the dispensing wheel will be released from its engagement with thesecondary lever arm and be able to rotate. The length of the rotation isdetermined by the length of the peripheral groove section. This lengthshould correspond to the indication of one dispensed dose. Byfurthermore providing means for urging the wheels to rotate, for examplein the shape of a pre-stressed spring or similar device, the side of thegroove will always be in contact with the part of the secondary leverarm engaging the groove. By the next radial movement of the secondarylever arm the wheel will again be released and be able to rotate theequivalent of a peripheral section's length.

This embodiment is especially advantageous in that the dispensingmechanism does only require the absorption of small and negligibletolerances in that the formation of the groove will dictate the movementof the indicating wheel.

In a further advantageous embodiment the peripheral sections of thegroove have different and increasing lengths along the periphery of thewheel. Hereby it becomes possible to have an unlinear indication on theindicating wheel. This is especially advantageous in that when thedevice is new and unused the user is certain that a large number ofdoses is available. The interesting question to a user is, especiallywhen a large number of doses have been dispensed, how many doses areleft in the canister. It can therefore be advantageous to have an exactand clear indication of the number of doses remaining in the canisterwhen there is only a low number of doses left. This can be provided byhaving very short peripheral sections on the indicating wheel in thearea with a large number of doses left in the canister and relativelylonger sections when there are only a few doses left in the canister.Hereby is facilitated that the movement of the wheel is larger andthereby the indication clearer.

In a further advantageous embodiment the interconnected and alternatingradial and peripheral sections are arranged in a spiral on the surfaceof the at least one wheel. In this configuration it is possible to havean unlinear indication with a large number of doses, whereby theindicating wheel will do more than one revolution in order to indicatethe number of doses dispensed.

The invention furthermore comprises a method for counting dispenseddoses from a device as described above, wherein by depressing the leverarm which thereby rotates around the fastening point of the lever arm inthe housing, the protrusion comprising a first curve or circular sectiontranslating into a second curve or linear section translating into athird curve or linear sections slides on a secondary lever arm such thatthe secondary lever arm has an end part which engages means on at leastone of two indicating wheels arranged on a mutually perpendicularrotating axis such that the downward movement of the secondary lever armcreates a rotation on at least one indicator wheel.

In a further preferred embodiment of the invention, at least part of thedevice for example the housing, the cap and/or the lever arm is colouredor otherwise marked according to a predefined code representing aspecific drug contained in the canister. This embodiment is especiallyuseful for patients which suffer from different diseases at the sametime which require different medication. Also patients requiringdifferent concentrations of their medicament at different times, forexample a higher concentration before going to sleep, would also easierbe able to determine the correct device to use in any given situation.

By having a specific colour for the medication suitable for treatmentfor one disease or in a given time, the user will be able to recogniseand use the correct device according to the symptoms.

In some of the embodiments of the present invention, the canister iscompletely enclosed within the device whereby it is impossible for theuser to read information which may be printed on the outside of thecanister. This information can also be provided on the device, but as anadditional safety caution, a distinctive colour coding should also beprovided. This is due to the fact that in acute cases, the user havingmore than one device should not have any doubt as to which one to useaccording to the situation and as there furthermore is usually a highlevel of stress in these situations paired with perhaps readingimpairment requiring glasses it does provide an additional safety aspectto distinctively colour code the device itself.

Return Blocking Function

Often these types of devices comprise a dose counter such that thepatient will be able to keep track of how many doses are left in thedevice such that a new device or canister can be provided in due time.It is therefore important that when the patient dispenses a dose, onlyone dose is dispensed and at the same time only one dose is counted.

Due to inherent tolerances in production in order to keep productioncosts of these types of devices as low as possible, and furthermore as aconsequence of the play arising from a number of mutually cooperatingparts, it is sometimes possible to activate the bottom either from thenon-depressed state or from the semi-depressed state, whereby the dosecounter may be activated without an actual dose being dispensed or adose may be dispensed without activating the dose counter.

For this type of device as for many other types of devices it isundesirable that depression of a button/lever, which is intended toeffect a function, i.e. initiate an event, where said function may havemore than one result, i.e. the example mentioned above, the activationof the button shall result in the dispensation of a dose and at the sametime counting/registration of said dose. It is paramount that both theseevents happening by depressing the bottom are reliable registered andcarried out without the possibility of unintended or intended tamperingwith the device.

Consequently, the present invention provides a mechanical returnblocking device comprising two cooperating and mutually displaceableparts:

-   -   a first part wherein parallel to a longitudinal axis at least        one set of tracks comprising a first track and a second track is        provided, and that the second track comprises one or more        retaining members and a sliding guide arranged at one end of the        second track;    -   a second cooperating part wherein a leg member comprising an        engagement section for engagement with the tracks provided on        the first part is provided, and that said leg member is biased        towards the first part and that the engagement section is        adapted to travel in the direction of the longitudinal axis;        and further that the retaining members allows the engagement        section of the leg member to move in a first direction towards        the sliding guide but blocks movement in the opposite second        direction and that the engagement section of the leg member        slides on the sliding guide, whereby the engagement section and        thereby the leg member is directed from the second track to the        first track.

The device thereby provides a first track where the engagement means cantravel unhindered in one direction. When built into a device where it isdesirable to have a complete button stroke, the engagement section willslide on the first track completely unhindered. During movement in thefirst direction the engagement section of the leg member will abut theside of the second track made up of one or more retaining members due tothe biasing force applied to the engagement section. Once the engagementsection reaches the bottom of the intended travelling strokecorresponding to a stroke of the button/lever, the biasing force willpush the engagement section onto the second track and the engagementsection will move in a second direction towards its starting positionand thereby pass the one or more retaining members.

Should a user during the movement in the second direction of theengagement means alter the direction, i.e. try to depress thebutton/lever again, the engagement section will engage the retainingmembers, whereby relative movement of the two cooperating parts will beimpossible.

Should a user during the depression of a button corresponding to theengagement section moving in the first track change direction, i.e. fromfirst to second direction, such that the engagement section begins amovement in the opposite direction, the biasing force will urge theengagement section onto the second track such that further forwardmovement will be hindered by the engagement section's position in thesecond track where one or more retaining members are provided, wherebyfurther movement in the first direction is impossible.

In order to again move the engagement section in the first directioncorresponding to pushing/activating the button or lever again, theengagement section must have been returned and the engagement sectionmust have been brought into contact with the sliding guide, whereby theengagement section during a further forward movement again will slide inthe first track abutting the retaining members on the way to completingan activation of the event by the button/lever.

In this manner by designing the one or more retaining members in such away that the event which should be triggered by activating thebutton/lever will only take place once one or more of the retainingmembers have been passed in the first direction, it can be assured thata reliable action when depressing the button/lever is facilitated. If adepression of the button/lever is disengaged during the travel, theengagement section as described above will be forced into the secondtrack and will by further movement in the first direction engage theretaining members making travelling in that direction impossible.

Therefore by arranging retaining members correctly, play in the deviceand tolerances can be counteracted, whereas a movement of thebutton/lever for activation or initiating of the event will reliably becarried out by the device. Tolerances and play in the device aretherefore assimilated by the initial movement of the engagement sectionin the first track and once it enters the activation zone, it is due tothe construction of the device impossible to turn back and reactivatewithout a complete return to the starting position. This in turn meansthat the activation should be provided for by a relatively shortmovement of the button/lever.

In a further advantageous embodiment each retaining member comprises aninclined sliding surface having a predetermined length along which theengagement section will slide, and a step in the shape of a surfacearranged at a sharp angle in relation to the sliding surface, said stepconnecting the top of one inclined sliding surface and the bottom of thenext sliding surface, such that a saw-tooth configuration is created,and such that the engagement section of the leg will be retained frommovement in one direction by said step.

This configuration is relatively simple to produce and further theconstruction can be made such that a user will feel the teeth of the sawtooth structure indicating that the button is in its return movement.When constructing the device itself it is relatively simple to designthe length of the sliding surface such that it will be designed exactlyfor the desired movement of the button/lever.

The formulation “step in the shape of a surface arranged at a sharpangle in relation to the sliding surface” shall in this context andwithin the application be understood as a surface at such an angle thatthe engagement section of the leg member travelling up the inclinedsliding surface, will fall down and be retained by this step, whichthereby hinders the movement in one direction and therefore only allowsthe engagement section to travel up the adjacent sliding surface if suchis provided.

In a further advantageous embodiment at least a part of a side surfacefacing the first track of each retaining member is arranged at a shallowangle in respect to the longitudinal axis of the device, such that theinclined sliding surface is narrowest in the end of the first travellingdirection of the engagement section.

In this embodiment it is provided that the side surface of the secondtrack, against which the engagement means abuts by movement in the firstdirection, is made such that the engagement means will not become stuckdue to unevenness or the like in that by arranging the side of theretaining member at a shallow angle, the engagement member which abutsthis side will continuously be pushed outwards during its movement inthe track.

In a further advantageous embodiment the inclined sliding surfaceoverlaps an adjacent inclined sliding surface, and the inclined slidingsurface tapers perpendicular to the longitudinal axis such that the topis narrower than the bottom of the sliding surface, whereby the step atthe bottom is narrower than the adjacent sliding surface at theirconnection point.

By this construction a wedge-shaped part of the inclined sliding surfaceis exposed next to the adjacent retaining means. During the reversemovement where the engagement section moves into engagement with theretaining means, the wedge-shaped section exposed by the taping sidesection facilitates the engagement sections travel into the retainingmeans.

In a still further advantageous embodiment the leg member is pivotallyfastened in the end opposite the engagement section, and that the firstpart comprising the at least one set of tracks has a correspondingcircular configuration arranged at a distance, whereby the engagementsection may engage the tracks.

It is obvious that the device described above will function where therelative movements between the first and second parts are linear. It ishowever also contemplated within the scope of the invention that the legmember can be pivotally fastened such that the engagement section willperform a movement corresponding to a partly circular movement. In orderto contain the retaining means at a distance from the engagement sectionof the leg, the retaining means may also be arranged on a circularshaped member, where the radius of the circle corresponds to thedistance between the pivotal fastening point of the leg member and theengagement section's outer tip. By this arrangement it is assured thatwhen the activation of the lever or button translating the action to theleg, the engagement section of the leg will stay in abutting contactwith the two tracks arranged on the first part. In this manner the sameadvantages are achieved as described above.

In a further embodiment the width of the sliding guide perpendicular tothe longitudinal axis at its widest section is at least as wide as theretaining members step.

By incorporating the mechanical return blocking device into devices ofthis type and designing the size and distribution of the retainingmembers according to the use, it can be achieved that once a useractivates the button or lever and moves it past the activation point, adose is dispensed and also optionally a dose counting device isactivated without the user being able to change direction. A change ofdirection necessitates that the button/lever is brought back to itsinitial starting position before a new stroke may be commenced.

In a further advantageous embodiment of the device the mutuallydisplaceable parts are formed as integral parts of the device, such thatthe first or second part is integral with part of the button arrangementand the other part is integral with a non moving part of the device.

This manner of production facilitates that the inventive advantages ofthe device are provided at very low costs in that the parts of thedevice can be moulded from the out-set with the two parts necessary inorder to create the mechanical blocking device. Furthermore in caseswhere the device is injection moulded, it is a very simple and therebycheap process to manufacture these added advantages into the deviceitself in that only the injection moulding tool has to be modified.

In a further advantageous embodiment the mechanical return blockingdevice is especially designed such that play and tolerances arising inthe device from production, assembly and manufacturing circumstances arecompensated by shaping and designing the engagement sections' travelbetween at least two adjacent retaining means or the retaining means andthe sliding guide corresponds to the activation of one event, where anevent may be the dispensation of a medicament dose and/or the input fora dose counting device.

By designing the device such that the event will take place only afterthe engagement section has past the last retaining means in the firsttrack, it can be assured that depression of the button/lever either willnot be completed and therefore the dose dispensation and dose countingwill not be activated, or the button/lever is depressed all the way pastthe activation point or points in one movement assuring the correctdispensation and counting of a medicament dose.

For some applications it will be desirable to produce the canister, thedose indicating activating means and the dose indicating means as oneintegral unit which cannot be disassembled without destroying one of thecomponents. The unit can advantageously comprise a part of the surfacesection of the housing. By this arrangement, the medicationcorresponding to the colour code of the section of the housing has notbeen replaced, altered or in any other way tampered with such that theuser can be assured that the medication in the canister corresponds withthe colour code and, furthermore, that the amount or number of indicateddoses in the dose indicating device corresponds to the amount or numberof doses in the canister.

In the inventive embodiments of the invention as described above, theinhaler has been described as comprising among other inventive featuresa yoke and a return blocking device. It should in this context be noted,however, that the principle of transforming the input from the lever armto the dose counter via the linear or non-linear configuration of theinterface between the lever arm and the yoke or the yoke and the inputmeans for the dose counter makes it possible, due to the increasedmovement of the lever arm in relation to the movement of the canister,to compensate for play and tolerances and also create/design adetermined firing action. Likewise, the same applies to the returnblocking device. The configuration/principle of assuring that themovement is completed in one action may also be used separately in othertypes of devices where such a feature may be desired.

BRIEF DESCRIPTION OF THE DRAWING

The invention will now be explained in more detail with reference to theaccompanying drawing. It should be noted however that the invention isnot limited to the specific embodiments as described above, but is onlylimited by the scope of the appended claims.

In the drawing

FIG. 1-3 illustrates a schematic first embodiment of the device in aclosed, open and activated position,

In FIG. 4, 5 and 6 a second embodiment of the invention is illustrated,

FIG. 7 illustrates a schematic construction of the dose indicator wheelarrangement,

FIG. 8 illustrates a schematic dispensing device,

FIG. 9 illustrates a schematic lever arm arrangement,

FIG. 10 illustrates an alternative groove configuration,

FIG. 11 illustrates an alternative groove configuration,

FIGS. 12-16 illustrate different embodiments of the dose indicationmeans,

FIG. 17 illustrates a cross-section of the device,

FIG. 18 illustrates a cross-section of an alternative embodiment of thedevice illustrated in FIG. 17,

FIG. 19 illustrates a mechanical return blocking arrangement,

FIG. 20 illustrates the central parts of the mechanical return blockingdevice,

FIG. 21 illustrates a sliding guide,

FIG. 22 illustrates the retaining means of the device, and

FIG. 23 illustrates a special configuration of the invention.

The same elements will be given the same reference numbers in alldrawings. The present invention is explained with reference to acanister containing the medication and a propellant. The canistercomprises a bottom, cylindrical sides and a top. The top comprises a rimwhere the cylindrical sides are assembled or merge with the top. In thetop is arranged a nozzle for dispensing the medication.

Inside the canister in immediate connection with the nozzle is arrangeda valve wherein the actual measuring of each dose to be dispensed takesplace.

As schematically illustrated in FIG. 4, the canister 6 comprises abottom 60 and cylindrical sides 61. Where the top 62 is joined with thesides 61, a rim 63 is formed. The nozzle is indicated by 7.

FIG. 1 is a principle sketch of how the device in one embodiment of theinvention can be mechanically constructed. The device 1 comprises ahousing 2, a cap 3 pivotally connected to the housing by a hinge-likeconstruction 4. Covered by the cap 3 is a mouthpiece 5 through which themedication contained in the canister 6 having nozzle means 7 can bedispensed.

In the figures the canister 6 is shown in an upside down position whichis to be understood that the nozzle means 7 of the canister are pointingdownwards.

A lever arm 8 is provided for reducing the force needed to press thecanister 6 against the seat 59 such that a medication dose will bedispensed.

The lever action in this embodiment is guided by three tracks 9, 10, 11arranged in the housing. In order to guide the lever 8 in the tracks 9,10, 11 pins 12 are provided perpendicular to the lever for guidance inthe tracks 9, 10, 11. In the closed position as illustrated in FIG. 1the cap 3 completely hides the mouthpiece 5. In this position no part ofthe lever arm projects outside the housing 2. For illustration purposes,the lever arm 8 in FIG. 1 has been indicated as projecting outside thehousing, but in the actual device the track 9 will be comprised insidethe housing and partly covered by the cap 3. Likewise the free end i.e.the end of the lever arm not connected with pins to a track is alsocompletely flush with the device. As can be seen from FIG. 1, the twotracks 9 and 10 are substantially horizontal. The third track 11comprises a linear section 13 and a curved section 14. The track 10 isprovided on a yoke-mechanism 15 connected to the lever arm. Theyoke-mechanism 15 comprises means 16 for engaging the bottom of thecanister 6.

Inside the cap 3 a cam 17 is provided in connection with the hinge-like4 connection between the cap and the housing. The cam 17 and the bottomof the yoke 18 are in abutting relationship when the cap is closed suchthat the means 16 for engaging the bottom of the canister cannot exertany pressure on the bottom of the canister and thereby inadvertentlydispense a dose into the cap.

When opening the cap as illustrated in FIG. 2 access is gained to themouthpiece 5. At the same time the yoke 15 is released from its abuttingrelationship with the cam 17 and due to the very low pressure caused bythe spring member 18, the means 16 for engaging the bottom of thecanister 6 are moved into a position where the means 16 very lightlytouches the canister 6.

At the same time the lever arm 8 is moved downwards because of theyoke's 15 downward movement due to the pressure from the spring 18 suchthat part of the lever arm 8 will project from the housing 2. Thismovement is guided by the three tracks 9, 10, 11 wherein the pins 12 canslide in respect of the movement caused by the lever arm.

In FIG. 3 the cap is in its completely open position whereby means 19having engaged the housing 2 and in this way blocked further movement bythe cap 3 in relation to the housing 2. The lever arm 8 can now easilybe depressed whereby a dose 20 can be ejected through the mouthpiece andinto the respiratory system of a user. When the lever arm is releasedafter the dose has been dispensed, the resiliency built into the nozzlesection of the canister will force the canister upwards into a positionas illustrated in FIG. 2. For this embodiment of the invention to work,it is very important that the resilient member 18 is weaker than themeans built into the canister for resetting into the closed position asillustrated in FIG. 2. The spring member 18 only serves to depress theyoke and thereby the engagement means 16 into abutting contact with thecanister 6 whereby the lever arm is moved from a stored position flushwith the housing to an exposed position where a part of the lever armprojects from the housing as illustrated in FIG. 2. The movement of thelever arm from the position as indicated in FIG. 2 to the positionindicated in FIG. 3 where a dose is disposed is done manually by theuser by griping the device, for example with the thumb on an abutmentsurface 21 on the cap and a forefinger on the projecting section of thelever arm 8 and forcing the lever arm downwards.

In FIG. 4-6 is illustrated how a canister is inserted into an embodimentof the invention. In FIG. 4 the device 1 is in its canister-receivingposition. In this position the integrated means 16 for engagement of thebottom of the canister and the lever arm 8 are opened by pivoting thelever arm around the pivotal connection 22. Hereby access is created tothe interior of the device 1. The cap 3 is closed and the mouthpiece 5is thereby covered.

In FIG. 5 the canister 6 is inserted into the housing 2 until it comesinto abutting contact with the cam 17 on the cap 3. It is therebyimpossible to insert the canister further into the housing. Thereafterthe lever arm 8 is pivoted as indicated by the arrow 23. The lever armin its free end, i.e. the end which is not fastened to the pivotalconnection 22, is supplied with a hook section 24. A corresponding gripsection 25 is provided on the housing 2 such that when the lever arm ispivoted into a closed position as illustrated in FIG. 6 the hook section24 will abut the grip section 25 such that the lever arm 8 by depressioncan move downwards but upwards movement is hindered by the hook and gripsections 24, 25. A spring-member 18 can be provided which spring-member18 abuts the lever arm 8 such that the hook section 24 when notdepressed is kept in contact with the grip section 25.

In order for the user to dispense a dose form the canister 6, it isnecessary to pivot the, cap 3 into its open position as illustrated inFIG. 3 whereby the cam 17 comes out of its abutting relationship withthe top of the canister 6. By depressing the lever arm 8, the nozzle ofthe canister 6 will dispense a dose.

In the two embodiments illustrated above access for the user to thecanister is hindered either because of the closed nature of the housing2 as illustrated in FIG. 1-3 or by the hook and grip sectionsillustrated in FIG. 4, 5 and 6. The snap-joint created by the hooksection 24 and the grip section 25 effectively avoids unintended accessto the interior of the housing and thereby to the canister by a user. Onthe other hand, the snap-joint provides for the possibility ofmanufacturing the device in a place different from the mounting of thecanister into the device such that devices can be produced in one place,canisters in a second place and the whole assembly of the device andcanister can take place in a third location. The snap-joint furthermoreprevents a user from removing a canister from the device. Hereby isavoided that the colour-coding or other means of indicating what kind ofmedication is contained within the housing does not correspond to thecanister actually is comprised in said housing.

In FIG. 7 two indicator wheels 30,31 are indicated arranged on mutuallyperpendicular rotating axis 32,33. The first indicator wheel 30 hasmeans for engagement 34 arranged such that the indicator engagementmeans provided for example by a second lever arm can rotate theindicator wheel 30 one step at a time. The indicator wheel 30 can beequipped with numbers or other means for indicating the number of dosesleft in the canister. This indication would be arranged on the rim 35 ofthe wheel. As the indicating wheel 30 is rotated around the axis 32, themeans 36 will per revolution push the second indicating wheel 31 onestep. This is caused by the engagement means 37.

The indicator wheel 31 will have its dose indicating numbers or colourson a front surface 38 of the wheel 31. As the wheel 30 rotates, thenumbers from 0 to 9 could for example be indicated on the rim 35. As theengagement means 36 engages the engagement means 37 provided on thesecond indicator wheel 31, this will cause movement of one notch on theindicator wheel 31. By providing the second indicator wheel 31 with thenumber 1 to the number of doses in a canister divided by 10, it becomespossible to indicate exactly the number of doses dispensed oralternatively the number of doses left in the canister. This is due tothe fact that the engagement means 36 will push the engagement means 37one notch and thereby add or subtract a factor 10 from the indicatingmeans provided on the surface 38 of the indicator wheel 31.

Turning now to FIG. 8, alternative means for registering and indicatingthe dispensation of a dose is indicated. The canister 6 is herebyschematically arranged in contact with a lever arm 39. The lever arm hasan end part 40 which engages a groove provided in a surface 42 of anindicating wheel 43.

By depressing the canister 6 translation of the downward movement by themeans here schematically indicated as a box 44 will translate thismovement into a movement of the end of the secondary lever arm 40 suchthat the end of the lever arm will move gradually towards the centre 45of the indicator wheel 43. Due to the means 46 provided for urging theindicating wheel 43 to rotate in the direction indicated by the arrow A,the peripheral section 47 of the groove 41 will move past the end of thelever arm 40 until the radial section 48 of the groove engages the endof the lever arm 40 and thereby stops further rotation. By arrangingsuitable indication means on the indicating wheel 43 the rotation of theindicating wheel 43 can correspond to indicating one dose dispensed.

By varying the length a of the peripheral sections, it will be possibleto have an unlinear representation of the number of doses dispensed.

In FIG. 10 and 11 alternative configurations of the groove areillustrated. The main principle of the groove is the provision of radialsections or notches interconnected with groove sections allowing the endof the secondary lever arm to be stopped by the radial sections and thewheel to rotate through the interconnecting groove sections.

In FIG. 9 an alternative embodiment for activating the dose indicatingmeans is illustrated. A mechanism for activating the secondary lever armengaging the indicating wheel is illustrated. The lever arm 8 being thesame lever arm as described above with respect to the embodimentsillustrated in FIGS. 1-6 is equipped with a protrusion consisting ofthree distinct sections. A first section 50 being in the shape of acurve or circular translating into a second section 51 preferably curvedshaped or linear translating into a third section 52 being curved orcircular in shape. These sections engage a protrusion 53 provided on asecondary lever arm 54 such that depression of the secondary lever armwill occur in three distinct movements. Firstly by engaging the firstsection 50 any slack between the end of the lever arm 55 and meansarranged on an indicating wheel 34 will be absorbed. As the protrusion53 slides on the second surface 51, the actual depression and therebymovement of the indicating wheel 30 will occur. As the lever arm 8 isfurther depressed, the protrusion 53 will slide on the surface 52whereby the pressure created by the end of the lever on 55 on the meansfor engagement 34 will lessen and the rotational movement of theindicator wheel 30 will subside. Hereafter the dose is completelydispensed and the user will release the lever arm 8, whereby it will bepushed back into its original position by the spring member 18 and atthe same time release the end of the lever arm's 55 engagement with themeans 34 such that the lever arm 54 can move back into the positionindicated in FIG. 9.

The box indicated in FIG. 8 by reference number 44 can be constructed ina similar fashion as illustrated schematically in FIG. 9.

In FIGS. 12-16, an alternative embodiment of the indicating means isillustrated. FIG. 12 illustrates a front cover 70 comprising a windowarea 71. FIG. 13 illustrates a front wheel 72 on which the numbers 0-12have been arranged on a peripheral section along the periphery of thewheel. Next to each number is a window 73 provided.

It should, however, be noted that rollers provided with numbers mayreadily be arranged instead of the wheels used in this particularembodiment.

In FIG. 14 a back wheel 74 is illustrated. Along the periphery of thewheel, the numbers 0-9 are provided twice. By superposing the two wheelsand the front cover, it will be possible to view the numbers through thewindow 71 in the front cover such that the numbers on the front wheel 72as well as the numbers provided on the back wheel 74 will be visiblethrough the window 73 such that the actual number, i.e. the combinationof the number on the front wheel 72 and the number on the back wheel 74will be visible through the window 71.

In FIG. 15 the window 71 is illustrated, wherein the numbers on thefront wheel 72 are visible along with the window 73 provided in thefront wheel such that the numbers 76 on the back wheel 74 are visiblethrough the window 71 in the front cover and the window 73 in the firstdisk becomes visible. In the illustrated example “120” doses areremaining in the canister.

Naturally, the disks can be arranged to count upwards or downwards,depending on choice. Likewise, the numbers can be given any suitablecolour or different colours.

In FIG. 16 is illustrated a special embodiment where the front wheel 72has a smaller radius than the back wheel 74.

A method of assembling the device may comprise the following steps:

-   -   the cap means are brought into its closed position, and if an        access lid is provided in the top of the housing for allowing        access through an opening to the interior of the housing this        lid is removed from said opening;    -   the pivotal engagement means are pivoted away from the housing,        thereby allowing access to canister receiving means arranged        inside the housing, where the canister receiving means comprises        a seat means for receiving the top end of a canister, and means        for guiding the canister inside the housing;    -   a canister is inserted into the housing with its top down i.e.        its ejecting nozzle first, such that the top nozzle of the        canister engages the seat;    -   optionally a spring member is arranged on a spring seat or the        engagement section, said spring members free end projecting        upwards;    -   the engagement means and optionally the lever arm is pivoted        into abutting contact with the bottom of the canister,        optionally compressing the spring member, and thereby either        engages a snap joint or where a lid is provided, the lid        optionally compressing the spring member is replaced on the        housing.

In FIG. 17 is illustrated a cross-section through an inhalation device1. The lever 77 is formed with an integral engagement point 78, whichengagement point engages a translating yoke 79 on a top surface of saidtranslating yoke. The translating yoke is connected to a secondary lever80, which will create input for the dose counting device (notillustrated). By configuring the top surface 81 of the translating yoke79 in a particular manner, the input movement from the lever 77 can betransformed to any desired input via the secondary lever 80.

In the configuration illustrated in FIG. 17 the entire top surface 81 ofthe translating yoke 79 is linear having a constant pitch. Therefore,when activating the lever 77 to pivot about the pivot point 82, thelever will perform the movement as indicated by the arrow 83 into theposition corresponding to the lowermost point of the stroke illustratedby dashed lines 84.

Turning to FIG. 18 a corresponding device is illustrated, but the topsurface 81 of the translating yoke has been divided into three separatelinear sections 85, 86, 87. As the engagement point 78 travels along thefirst section 87 due to rotation of the lever 77 about the pivot point82, the translating yoke 79 will only perform a very slight downwardmovement.

As the engagement point 79 engages the steeper second section 86, asubstantial part of the translating yoke's downward movement will beperformed as the engagement point 78 travels along section 86. As theengagement point 78 engages the third surface 85, the translating yokewill again only perform a very slight movement due to the almosthorizontal travel of the engagement point in relation to the thirdsurface 85.

In this particular configuration the first section 87 may be used toabsorb slack and tolerances built into the device, such that whenactivating the device in order to dispense a dose, i.e. passing the firepoint, a determined movement by the secondary lever arm 80 will beaccomplished due to the fact that any slack and tolerances already areabsorbed by the engagement point's travel along the first section 87.

The device may further be provided with a mechanical return blockingarrangement, as illustrated in FIG. 19.

A typical inhalation device comprises a mouthpiece 88, an activatingbutton 89, above reference is made to a lever arm 8,77, a canister 90comprising the medication to be dispensed through the mouthpiece 88.This and other embodiments of the invention have been explained above.By depressing the button 89, the canister 90 will be forced downwardsand via a valve device 91 a dose will be dispensed through themouthpiece. In the embodiment described with reference to FIGS. 19-23, amechanical return blocking device is arranged such that a leg 92 isintegrated in the button 89 (or lever arm). The return blocking devicecomprises two parts; A first part 95 and a second part 92 which byinteraction create the return blocking device. The button 89 is designedto pivot about the pivot point 93. By the movement of the engagementsection 94 of the second part will abut the first part 95 which isintegral with the inhalation device.

In FIG. 20 is illustrated two cooperating parts making up the centralparts of the mechanical return blocking device. A first part 95 and asecond part 92. The two parts 95,92 are intended to be mutuallydisplaceable such that the first part 95 will be able to slide inrelation to the second part 92.

Which part slides in relation to which other part does not influence theproper workings of the device.

On the first part 95 is provided a number of retaining means 97, whereeach retaining means in the illustrated embodiment comprises an inclinedsliding surface 98, which is connected with a step 99, see FIG. 21. Thestep connects the top of one inclined surface 98 with the bottom of anadjacent inclined surface arranged on an adjacent retaining means. Theretaining means is furthermore provided with a tapered surface 100.

Foremost in front of the retaining means 97 is arranged a sliding guide101. The sliding guide tapers in the first direction such that the rearend 102 of the sliding guide will have the same width in a directionperpendicular to the first direction as indicated by the arrow 96 as thewidth of the inclined surface 98, whereas the taper brings the width tonear 0. This tapered sliding guide can be seen more clearly in FIG. 21.

The second part comprises a leg 92, which is biased toward the firstpart 95 such that an engagement section 94 may engage the retainingmeans 97.

As the two parts 95,92 are mutually displaced, for example from theposition illustrated in FIG. 20, the engagement section can only move tothe left in relation to the first part in that the retaining means 97will hinder any movement of the engagement section and thereby thesecond part 92 to the right. As the engagement section comes to the endof the sliding guide 101, the engagement section will be guided onto thefirst track illustrated by the plane surface 102. In the illustratedexample the second track is made up of the row of retaining members 97.

As the engagement means 94 are engaged toward the tracks, i.e. the rowof retaining means 97 and surface 103, the engagement means will slideon the surface 103 when the first part 95 is moved to the left inrelation to the leg member 92. Due to the biasing of the leg member 92,engagement section 94 will abut the side surfaces 104 of the retainingmeans. If the relative movement of the two sections is stopped and thedirection altered, the engagement section 94 will slide up the exposedpart of the inclined surface on the retaining means and the engagementsection will slide into a position equivalent to the one illustrated inFIG. 20, whereby further movement to the right becomes impossible.

If however the relative movement of the two members 95,92 is continuedfrom the start to a position past the activation point, the entiremovement can be completed without any hindrance from the retaining means97. On the return journey the engagement means will slide over the rowof retaining means 97 until it reaches the sliding guide 101, wherebyaccess to the first track will be free again for the engagement means.

In FIG. 22 an embodiment is illustrated where the retaining means 97 isarranged on a part of a circular member 104. When the leg 92 is arrangedto pivot about a point as illustrated for example in FIG. 19, theengagement section 94 of the leg will describe part of a circle duringits movement. By arranging the retaining means 97 on a circular member104, where the distance between the pivot point and the circular member104 is kept constant, the mechanical blocking device will function in amanner completely analogue to the one described with respect to FIG. 20.

In FIG. 23 a special configuration of the invention is illustrated. Inthis configuration the mechanical blocking device is equipped with oneretaining means 97 and one sliding ramp 101. This embodiment functionsin exactly the same way as described above and is especially intendedfor cases where the construction shall insure that one event definitelytakes place. The embodiment may, as is the case with all featuredembodiments, be made as illustrated with two sets of tracks on eitherside of the middle divide 105, but may also be manufactured with only asingle retaining means and a single sliding guide and a first track 103.

1. Inhaler device (1) for dispensing a medicament from a pressurisedcanister (6), where said device comprises a mouthpiece (5) arranged in ahousing (2), where said housing (2) substantially encloses the canister(6), where a lever arm (8, 77) is provided, where said lever arm (8, 77)comprises means (16) for engaging the bottom of the canister (6) suchthat said lever arm (8, 77) may be activated by a user in order todispense a dose, characterised in that the lever arm (8, 77) furtherengages a yoke (15, 79) where the transfer of movement from said leverarm (8, 77) due to the activation of said lever arm to the yoke (15, 79)is linear and/or non-linear, and that the yoke (15, 79) comprises means(44, 80) for transferring the movement to a dose counting mechanismarranged in the housing.
 2. Inhaler device according to claim 1,characterised in that the movement of the canister (6) caused by saidlever arm (8, 77) in order to dispense a dose is shorter that thecorresponding movement of said yoke (15, 79).
 3. Inhaler device fordispensing a medicament from a pressurised canister (6), where saidcanister (6) comprises a bottom and a top, and that a valve mechanism(7) is provided in the top of said canister (6) for dispensing amedicament and that in use the canister is placed with the top downwardsproximate a mouthpiece (5), where the device comprises a mouthpiece (5)and a means for guiding and/or holding the canister, and a lever arm (8,77) comprising means (16) for engagement with the bottom end of thecanister (6), such that the canister (6) is not accessible from theoutside, and further that a seat for engagement with the top of thecanister (6) is provided inside the housing (2), and a cap (3) ispivotally arranged such that the cap (3) can be pivoted into a closedposition where it covers the mouthpiece (5) and an open position wherethe mouthpiece (5) is accessible, and that said cap (3) furthercomprises means (17) for abutting the top of the canister (6) and/or forabutting the means (15, 16, 79) for engagement with the bottom end ofthe canister (6) when the cap (3) is in its closed position such thatthe canister (6) cannot be activated accidentally.
 4. Device accordingto claim 3, characterised in that the means (16) for engagement with thebottom of the canister comprises a yoke (15) which yoke has a canisterengagement section (16) optionally having a shape corresponding to thebottom of the canister (6), and an end section, which when the cap (3)is in its closed position engages a cam (17) provided on the cap (3),such that the engagement section (16) of the yoke (15) is not in contactwith the canister (6).
 5. Device according to claim 3, characterised inthat the lever arm (8, 77) is guided by three tracks (9, 10, 11)provided on the inside of the housing (2) where the guidance comprisespins (12) arranged on the lever arm (8, 77) perpendicular to the leverarm's longitudinal direction, and that said pins (12) engages the tracks(9, 10, 11) and preferably identical sets of tracks arrangedsymmetrically on either side of the lever arm; a first track or set oftracks (9) in front of the canister (6) which track is generallyhorizontal; a second track or set of tracks (10) provided in the yoke(15), said track also being generally horizontal and a third track orset of tracks (11) arranged behind the canister (6) and said third track(11) comprises a generally straight upper section (13) and a curvedlower section (14).
 6. Device according to claim 3, characterised inthat the length of the lever arm (8) is such that when the cap (3) isclosed the free end of the lever arm (8) is flush with or containedwithin the housing (2), and when the cap (3) is opened the free end ofthe lever arm (8) will project from the housing (2).
 7. Device accordingto claim 1, characterised in that the lever arm (8, 77) is a pivotalsection of the housing (2) constituting at least part of a top surfaceof the device and that the lever arm (8, 77) is pivotably fastened tothe housing (2) in one end of said lever arm (8, 77).
 8. Deviceaccording to claim 1, characterised in that a dose counting mechanism isarranged inside the housing (2), such that a member (44, 54, 80)optionally engaging the canister will be depressed together withdepression of the lever arm (8), and that said member will transmit thedepression to a dose counter for registration of a delivered dose, andthat the dose counter mechanism comprises means (30, 31, 72, 74) visibleon the housing for indicating the number of dispensed doses or number ofremaining doses.
 9. Device according to claim 1, characterised in that adose counter is provided, and that said dose counter comprises:indicating means (30, 31) for indicating the available content in acanister (6), which means comprises one or more indicating wheels orrollers (30, 31, 72, 74); a secondary lever arm (40, 54) having means(55) for engaging at least one of the indicating wheels or rollers (30,31, 72, 74); a pivotable activating member which may be integral withthe lever arm (8) comprising a first linear curve or circular section(50) translating into a second linear curve or circular section (51)translating into a third linear curve or circular section (52), arrangedsuch that the secondary lever arm (40, 54) will abut and slide on saidsections (50, 51, 52) during a count.
 10. Device according to claim 8,characterised in that a groove (41) is arranged in a surface (42) of atleast one of the wheels (43) at a distance from the rim, said groove(41) comprising spaced radial sections (48) connected with curved orlinear sections (47) arranged such that a part of the secondary leverarm (40) is inserted and slidably arranged in said groove (41); means(46) for urging at least one wheel to rotate.
 11. Device according toclaim 1, characterised in that the pivotably fastened lever arm (8, 77)has an engagement point (78) which engages a yoke (79), which yokecomprises a projecting member (80) which is adapted to engage asecondary lever arm having means for translating the movement of theprojecting member (80) to a dose counting mechanism, where theengagement point (78) engages the yoke (79) on an upper surface (81, 85,86, 87) of said yoke.
 12. Device according to claim 11, characterised inthat the upper surface (81, 85, 86, 87) of the yoke (79) is linear, suchthat the engagement point (78) transfers the movement of the pivotablymounted lever (77) in a linear movement to the yoke (79).
 13. Deviceaccording to claim 11 , characterised in that the upper surface of theyoke (79) is divided into two or more distinct linear or non-linearsections (85, 86, 87), where the lever arms engagement points' (78)travel along the second section (86) creates a substantial part of theyoke's (79) movement.
 14. Device according to claim 1 comprising amechanical return blocking arrangement where said blocking arrangementcomprises two cooperating and mutually displaceable parts (92, 95): afirst part (95) wherein parallel to a longitudinal axis at least one setof tracks comprising a first track (102) and a second track is provided,and that the second track comprises one or more retaining members (97)and a sliding guide (101) arranged at one end of the second track; asecond cooperating part (92) wherein a leg member comprising anengagement section (94) for engagement with the tracks provided on thefirst part is provided, and that said leg member is biased towards thefirst part (95) and that the engagement section (54) is adapted totravel in the direction of the longitudinal axis; and further that theretaining members (97) allows the engagement section (54) of the legmember to move in a first direction towards the sliding guide (101) butblocks movement in the opposite second direction and that the engagementsection (94) of the leg member slides on the sliding guide (101),whereby the engagement section (54) and thereby the leg member isdirected from the second track to the first track (102).
 15. A deviceaccording to claim 14, characterised in that in the blocking device eachretaining member (97) comprises an inclined sliding surface (98) havinga predetermined length along which the engagement section (94) willslide, and a step in the shape of a surface arranged at a sharp angle inrelation to the sliding surface (98), said step connecting the top ofone inclined sliding surface (98) and the bottom of the next slidingsurface (98), such that a saw-tooth configuration is created, and suchthat the engagement section (54) of the leg will be retained frommovement in one direction by said step.
 16. A device according to claim14 , characterised in that the inclined sliding surface (98) overlaps anadjacent inclined sliding surface, and that the inclined sliding surfacetapers perpendicular to the longitudinal axis such that the top isnarrower than the bottom of the sliding surface, whereby the step at thebottom is narrower than the adjacent sliding surface at their connectionpoint.